1. Field of the Invention
This invention relates to a receiver telephone having an automatic response capability. That is, when a receiving party is absent, a voice reply is automatically sent to the calling originator. The term absent as used herein means that the receiving party is either not present to answer his telephone or is otherwise unwilling or unavailable to answer the telephone. In particular, the receiver telephone will store a predetermined message sent by the calling originator and/or the originator's telephone number in response to a dual tone multifrequency (DTMF) signal also sent by the calling originator.
2. Description of the Prior Art
Various types of automatic telephone answering devices have been used in the prior art with the capability of sending an automatic voice reply to the calling originator when the receiving party is absent. Basically, if a call signal arrives at the telephone of an absent party, such telephone answering devices are designed to send a message to the calling originator indicating that the receiving party is absent and then to record a message from the calling originator. Upon returning, the party listens to the recorded message in order to determine who had telephoned him while he was absent.
In the prior art systems described above, the recorded message was made by recording the voice of the calling originator on a recording medium such as a magnetic tape. Such a system, however, is too large and bulky since voice signals, having an indefinite quality of information, are recorded, and since it is necessary to use a recording device incorporating magnetic tape or the like. At present, it is not possible to utilize a compact and suitable voice recording device.
In recent years, there has been an increasing demand for portable telephone sets, such as automobile and cordless telephones. There is a need that these wireless telephones also have an automatic response capability for automatically recording the message from the calling originator. It is not possible, however, to use prior art answering devices with a wireless telephone due to its size and handling inconvenience.
One technique for overcoming the problem is disclosed in the commonly assigned U.S. patent application Ser. No. 613,646 filed May 24, 1984, which is incorporated herein by reference. That application incorporates computer control technique and associated read-only and random-access memories to overcome the size and handling problems discussed above.
Briefly stated, according to that application, instead of directly recording a voice signal from a remote party, a message from the remote location is transmitted by depressing a key (e.g., a push button) to the telephone apparatus of the receiving or called party. In particular, in response to depressing the key, a DTMF signal corresponding to a particular message is transmitted to the receiving party. Upon decoding the DTMF signal, it is stored in a memory device of the receiving party's telephone device. The term DTMF signal comprises a combination of two voice frequency signals generated for the purpose of identifying the particular depressed keys of the remote telephone apparatus. The term message from the remote party means the telephone number of the calling originator and/or other predetermined message sent by the calling originator. That is, predetermined messages can be generated by depressing respective keys of the telephone apparatus (e.g., "please telephone me" or "I will telephone again").